Study of the thermal field and thermal stress field of typical BGA packaging by numerical simulation

A typical 3D-BGA packaging model was set up and numerical simulation method was used to study its thermal field and thermal stress field distribution when chip works on a given power. Different heat convection coefficients and packaging materials had been applied to study their effects on the temperature and stress field. The results show that the influence on the temperature and stress field decreases with the increasing heat convection coefficients. On the study of the thermal stress and strain field, the maximum strain occurs at the edges region of the packaging, but the maximum stress appears on the top surface of sub-center ball because of the structural design with a cover shell, and it limits the occurrence of large deformation in some extent. This paper shows the general rules when BGA packaging model works, and helps to design advanced and reliable packaging structure.